[BiturboS4] Abt Chip Specification

[Robin St.Clair]

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David

I have attached a .pdf with the torque and horsepower curves for the Abt
chip. You will see that the key differences are:

Standard
Max Torque            400 NM from 1,860 - 3,600 rpm
Max Horsepower   265 PS at 5,800 rpm

Modified
Max Torque            505 NM at 3,100 rpm (over 500 NM from 2,000 - 3,850
rpm)
Max Horsepower   310 PS at 5,200 rpm

Your Measured Figures using an Accelerometer are:

Without Abt Chip
Max Torque            38.19 mkgF at 3,801 rpm (375 NM)
Max Horsepower  266.9 PS at 6,090 rpm

With Abt Chip
Max Torque           47.83 mkgF at 3,981 rpm (469 NM)
Max Horsepower  317.6 CV at 5,530 rpm

Your Recent Measurement Figures using a Dynamometer

Without Abt Chip
Max Torque             418.0 NM at 3,200 rpm
Max Horsepower   191.9 kW at 5,500 rpm (261 PS)

With Abt Chip
 Max Torque            433 NM at 4,900 rpm
Max Horsepower  223.0 kW at 5,400 rpm (303 PS)

To me these figures show that either the temperatures were excessive and the
engine was heat soaked or you have something wrong. Did they force air into
the intakes and intercoolers? Do try lifting the bonnet when the engine is
running, is it excessively noisy, do you hear a rasping sound, you could
have problems with the turbos or a torn Throttle Body Boot, where the air
coming into the engine is controlled, its a common failure and a modified
part is now available.

It would be best to have the engine rectified and then measure the
horsepower and torque at the wheels, without any corrections, then just
concentrate on the differences between the two sets of measurements, not the
absolute values. Its very important when testing a turbo car on a dyno, not
to let the engine get heatsoaked, so just a quick test run and then off with
cold air directed at the intakes and intercoolers.

The spikes at low speed are most likely slippage/gearchanging. Message to
all Dyno operators, do try hydraulic dynos, safer, quieter, more accurate
and portable.

The distortions in the figures from your most recent measurement are quite
possibly caused by the tester adjusting the measured at the wheel horsepower
and torque figures to something approaching the production specification,
when the engine is not 100 % operating correctly. Have you had the check
codes examined by an expert, the TBB failure throws codes which can look
like damaged turbos. Remove the throttle body boot and inspect it for tears,
take great care not to tear it when replacing it, its easy to damage it.

Optimax is a Shell product available in all gas stations which is 99 Plus
Octane, turbos love it.

HTH

R+C
PS  my car had a torn TBB, it was down about 15 PS, showed turbo failure
codes and sounded too noisy,  repaired the TBB and overhauled the turbos and
once more the car pulls 289kph in top on Optimax

From: "David" <goodson at menta.net>
To: <biturbos4 at audifans.com>
Subject: RE: [BiturboS4] Re: BiturboS4 digest, Vol 1 #68 - 1 msg
Date: Sat, 10 Aug 2002 12:45:09 +0200

First of all thank you very much to Robin and Dave for such a detailled
answer.
To Robin :
My S4 is a 1999, with 31000 km, the tuner knows it and the mod should
be the
adequate.
I'm using 98 gasoline, as the tuner said. I don't know about Optimax
gasoline, I've never seen it in Spain neither in France.
What is the exact role of the Throttle Body Boot? Is there a way to
check
its state by myself ?
Since it seems that I can't post attachments to this group, I've made
the
dyno results
available through this link (hope this works):
http://www.audi-sport.net/uploads/74907-David_s4.jpg
It may be important to add that the second test (after mod) have been
made
10 months after the first one, with different temperature conditions (
it
was 4=BAc hotter).
cheers.
David.

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